Heretofore, silver paste has been mainly used for bonding a semiconductor chip and a semiconductor chip mounting support member. However, with the downsizing and high performance of semiconductor chips and the downsizing and miniaturization of support members used, some problems have arisen with the method using silver paste, such as the occurrence of failures in wire bonding caused by the extrusion of paste or inclined semiconductor chips, the difficulty in controlling the film thickness of adhesive layers and the generation of voids in adhesive layers. Also, in the field of mobile devices where further miniaturization and a higher density are required, semiconductor devices in which a plurality of semiconductor chips are laminated have been developed and mass-produced, and the above problems tend to become apparent particularly when such semiconductor devices are produced. For the above reasons, film adhesives (hereinafter referred to as an adhesive film for a semiconductor) have been recently used instead of silver paste.
Examples of methods of producing a semiconductor device using an adhesive film for a semiconductor include: (1) a piece lamination process in which an adhesive film for a semiconductor which has been cut in any size is laminated on a semiconductor chip mounting support member such as a wiring board or a semiconductor chip, and a semiconductor chip is bonded thereto by thermocompression bonding; and (2) a wafer back-side lamination process, in which an adhesive film for a semiconductor is laminated on the back side of a semiconductor wafer and the resultant is cut into pieces with a rotary blade to prepare a semiconductor chip with an adhesive film, and the chip is bonded to a semiconductor chip mounting support member or a semiconductor chip by thermocompression bonding. Recently, to simplify the production process of semiconductor devices, the wafer back-side lamination process described in the above (2) has become the mainstream.
In the wafer back-side lamination process, it has been common to cut a semiconductor wafer on which an adhesive film for a semiconductor is laminated with a rotary blade as described above. However, cutting a semiconductor wafer and an adhesive film simultaneously by a general dicing method using a rotary blade has had the problem of the occurrence of cracks (chip cracks) at the edge of the semiconductor chip after cutting or the occurrence of much flash due to the rough section of the adhesive film. The presence of such chip cracks and flash makes it easier for semiconductor chips to be broken when they are picked up. In particular, picking up semiconductor chips cut from a thinned semiconductor wafer without cracks becomes difficult.
So recently methods have been proposed, in which a street for partitioning formed on the surface of a semiconductor wafer is cut so as to form a dicing groove and the back side of the wafer is ground to reach the bottom of the dicing groove, thereby dividing the semiconductor wafer into semiconductor chips (see, for example, Patent Documents 1 and 2). And the following methods are for forming an adhesive film having the same size as a semiconductor chip prepared by such a dicing-before-grinding process on the back side of the semiconductor chip.
(a) A method including preparing a laminate of a semiconductor wafer (a plurality of semiconductor chips) divided by a dicing-before-grinding process, an adhesive film for a semiconductor and a dicing tape, and dividing the adhesive film for a semiconductor by expanding the dicing tape by an expanding device.(b) A method including preparing a laminate of a semiconductor wafer (a plurality of semiconductor chips) divided by a dicing-before-grinding process and an adhesive film for a semiconductor, and cutting the adhesive film for a semiconductor with a laser dicer along a street (diced line) on the wafer surface.    Patent Document 1: Japanese Patent Application Laid-Open No. 2002-016021    Patent Document 2: Japanese Patent Application Laid-Open No. 2002-367933